Use of sunscreen combinations which comprise, as essential constituent, 2-(4-alkoxyanilinomethylene) malonic dialkyl esters as photosatble uv filters in cosmetic and pharmaceutical preparations

ABSTRACT

Use of sunscreen combinations which comprise, as essential constituent, 2-(4-alkoxyanilinomethylene)malonic dialkyl esters as photostable UV filters in cosmetic and pharmaceutical preparations  
     A) compound absorbing essentially in the UV-A region and  
     B) further compounds absorbing in the UV-A region, in the UV-B region and over both regions,  
      where the constituent absorbing in the UV-A region consists of  
     A) effective amounts of at least one of the compounds of the formula I  
                 
 
      in which the substituents R 1  to R 3 , independently of one another, are C 1 -C 8 -alkyl  
     as photostable UV filters in cosmetic and pharmaceutical preparations for protecting human skin and human hair against solar rays.

[0001] Use of sunscreen combinations which comprise, as essential constituent, 2-(4-alkoxyanilinomethylene)malonic dialkyl esters as photostable UV filters in cosmetic and pharmaceutical preparations.

[0002] The invention relates to the use of sunscreen combinations which comprise, as essential constituent, the 2-(4-alkoxyanilino-methylene)malonic dialkyl esters which absorb in the UV-A region, and at least one further sunscreen which absorbs in the UV-A region, UV-B region or in both regions, chosen from a group defined in detail below as photostable UV filter combination in cosmetic and pharmaceutical preparations for protecting the human epidermis or human hair against UV radiation, specifically in the range from 320 to 400 nm.

[0003] The sunscreens employed in cosmetic and pharmaceutical preparations have the task of preventing, or at least diminishing the consequences of, harmful effects of sunlight on the human skin. However, these sunscreens also serve to protect other ingredients from decomposition or degradation by UV radiation. In hair cosmetic formulations the aim is to reduce damage to the keratin fibers by UV rays.

[0004] The sunlight reaching the surface of the earth contains proportions of UV-B radiation (280 to 320 nm) and UV-A radiation (>320 nm), which are directly adjacent to the visible light region. The effect on the human skin is manifested, particularly in the case of UV-B radiation, by sunburn. Accordingly, the industry offers a relatively large number of substances which absorb UV-B radiation and thus prevent sunburn.

[0005] Dermatological investigations have now shown that UV-A radiation is also perfectly capable of causing skin damage and allergies by, for example, damaging the keratin or elastin. This reduces the elasticity and water storage capacity of the skin, i.e. the skin becomes less supple and tends to form wrinkles. The noticeably high incidence of skin cancer in regions where the sun's radiation is strong shows that damage to the genetic information in the cells is evidently also caused by sunlight, specifically by UV-A radiation. All these findings would therefore suggest the need to develop efficient filter substances for the UV-A region.

[0006] There is a growing demand for sunscreens for cosmetic and pharmaceutical preparations which can be used in particular as UV-A filters and whose absorption maxima ought therefore to be in the range from about 320 to 380 nm. In order to achieve the required effect using the minimum amount, sunscreens of this type ought additionally to have a high specific absorbance. Sunscreens for cosmetic products must also meet a large number of other requirements, for example good solubility in cosmetic oils, high stability of the emulsions produced with them, toxicological acceptability, and low intrinsic odor and low intrinsic color.

[0007] Another requirement which sunscreens must meet is adequate photostability. However, this is only inadequately ensured, if at all, with the UV-A-absorbing sunscreens hitherto available.

[0008] French Patent No. 2 440 933 describes 4-(1,1-dimethylethyl)-4-methoxydibenzoylmethane as a UV-A filter. It is proposed to combine this specific UV-A filter, which is sold by GIVAUDAN under the name “PARSOL 1789”, with various UV-B filters in order to absorb all UV rays having a wavelength from 280 to 380 nm.

[0009] However, this UV-A filter does not have sufficient photochemical stability, when used alone or in combination with UV-B filters, to ensure sustained protection of the skin during sunbathing for prolonged periods, which means that repeated applications at regular and short intervals are required if effective protection of the skin from all UV rays is desired.

[0010] For this reason, EP-A-0 514 491 discloses the stabilization of the insufficiently photostable UV-A filters by adding 2-cyano-3,3-diphenylacrylic esters which themselves act as filters in the UV-B region.

[0011] It has furthermore already been proposed in EP-A-0 251 398 and EP-A-0 416 837 to combine chromophores absorbing UV-A radiation and UV-B radiation into one molecule using a linker. This has the disadvantage that firstly a free combination of UV-A and UV-B filters in the cosmetic preparation is no longer possible, and that difficulties in the chemical linkage of the chromophores allow only certain combinations.

[0012] It is an object of the present invention to propose sunscreens for cosmetic and pharmaceutical purposes which absorb in the UV-A region with high absorbance, which are photostable, have low intrinsic color, i.e. a sharp band structure, and are soluble in oil or water depending on the substituent.

[0013] We have found that this object can be achieved advantageously by certain sunscreen combinations.

[0014] Accordingly, this object is achieved according to the invention by the use of sunscreen combinations comprising a

[0015] A) compound absorbing essentially in the UV-A region and

[0016] B) further compounds absorbing in the UV-A region, in the UV-B region and over both regions,

[0017]  where the constituent absorbing in the UV-A region consists of

[0018] A) effective amounts of at least one of the compounds of the formula I

[0019]  in which the substituents R¹ to R³, independently of one another, are C₁-C₈-alkyl

[0020]  and the constituent

[0021] B) comprises effective amounts of one or more compounds chosen from the group consisting of

[0022] Ba) hydroxybenzophenones of the formula II

[0023]  in which the substituents, independently of one another, have the following meanings:

[0024] R⁴ and R⁵

[0025] are hydrogen, C₁-C₁₂-alkyl, C₃-C₁₀-cycloalkyl, where the substituents R⁴ and R⁵ may, together with the nitrogen atom to which they are bonded, form a 5- or 6-membered ring and

[0026] R⁶ hydrogen, C₁-C₁₂-alkyl, C₃-C₁₀-cycloalkyl;

[0027] Bb) diarylbutadienes of the formula III

[0028]  in which the substituents R⁷ and R⁸, independently of one another, may be hydrogen, C₁-C₁₂-alkyl or C₃-C₁₀-cycloalkyl,

[0029] Bc) the compound of the formula IV

[0030] Bd) the compound of the formula V

[0031] Be) the compound of the formula VI

[0032] Bf) the compound of the formula VII

[0033] Bg) an organosiloxane benzalmalonate of the formula VIIIa

[0034]  in which

[0035] V₁′ is the group

[0036] V₁ is a methyl group or V₁′, or of the formula VIIIb

[0037]  in which V₂′ is the group of the structure

[0038] V₂ is a methyl group or V₂′

[0039]  or mixtures of compounds of the formulae VIIIa and VIIIb,

[0040] where t is a value up to 100 and u is a value up to 20, with the proviso that u=0 when V₁=V₁′ and/or V₂=V₂′, and u is a value from 1 to 20 when V₁=CH₃ and/or V₂=CH₃,

[0041] Bh) the compound of the formula IX

[0042] Bi) the compound of the formula X

[0043] Bj) the compound of the formula XI

[0044]  in which X is hydrogen, sodium, potassium, ammonium or triethanolammonium,

[0045] Bk) the compound of the formula XII

[0046] as photostable UV filters in cosmetic and pharmaceutical preparations for protecting human skin or human hair against UV rays, in particular against natural solar rays, optionally together with further compounds which absorb in the UV region and which are known per se for cosmetic and pharmaceutical preparations.

[0047] Alkyl radicals R¹ to R³ in compound I which may be mentioned are branched or unbranched C₁-C₈-alkyl chains, preferably methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, n-heptyl or n-octyl. Preferred radicals for R¹ to R³ are methyl, ethyl, n-propyl and 1-methylethyl.

[0048] Alkyl radicals R⁴, R⁵ and R⁶ in compound II which may be mentioned are branched or unbranched C₁-C₁₂-alkyl chains, preferably methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl1-methylpropyl, 1-ethyl-2-methylpropyl, n-heptyl, n-octyl or 2-ethylhexyl.

[0049] Particularly preferred alkyl radicals which may be mentioned for R⁴, R⁵ and R⁶ are methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 2-ethylhexyl.

[0050] Alkyl radicals R⁷ and R⁸ in compound III which may be mentioned are branched or unbranched C₁-C₁₂-alkyl chains, preferably methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, n-heptyl, n-octyl or 2-ethylhexyl.

[0051] Particularly preferred alkyl radicals which may be mentioned for R⁷ and R⁸ are methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 2-ethylhexyl.

[0052] Cycloalkyl radicals which may be mentioned for R⁴ to R⁸ in formulae II and III are preferably branched or unbranched C₃-C₁₀-cycloalkyl chains, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, 1-methylcyclopropyl, 1-ethylcyclopropyl, 1-propylcyclopropyl, 1-butylcyclopropyl, 1-pentylcyclopropyl, 1-methyl1-butylcyclopropyl, 1,2-dimethylcyclopropyl, 1-methyl-2-ethylcyclopropyl, cyclooctyl, cyclononyl or cyclodecyl.

[0053] Particularly preferred cycloalkyl radicals for R⁴ to R⁸ which may be mentioned are C₃-C₆-cycloalkyl radicals, very particularly preferably cyclopropyl, cyclopentyl and cyclohexyl.

[0054] The sunscreen combination of the compounds (A) and (B) can be used alone or in combination with further compounds which absorb in the UV region, although at least effective amounts of the compounds (A) and (B) should be present in the sunscreen preparations. Effective amounts of the compounds (A) and of the compounds (B) is generally to be understood as meaning in each case at least 0.1% by weight, in each case based on the cosmetic preparation.

[0055] In the sunscreen combinations according to invention, the amount of compounds which absorb in the UV-B region usually predominates. Accordingly, the content of the compound (A) which absorbs in the UV-A region is generally 5 to 50% by weight, preferably 10 to 25% by weight, in each case based on a sunscreen combination of (A) and (B).

[0056] The sunscreen combinations are characterized by their high photostability, and the preparations prepared with the sunscreen combinations are characterized by their pleasant feel on the skin. The sun protection factors achieved with the combinations are considerably higher than the additive values of the individual UV filters. Even the UV-A protection performance of the sunscreen combinations according to the invention—with regard to the critical wavelength, the PPD value (persistent pigment darkening), the IPD value (immediate pigment darkening), and the UVA/UVB ratio—is higher than that which can be achieved by the known UV filters according to the prior art.

[0057] The compound of the formula I is described in U.S. Pat. No. 6,069,170 as a constituent of cosmetic preparations. Moreover, in column 3 of said patent, lines 5 to 27, it is mentioned that it is possible to use the compound group to which the compound of the formula I belongs together with known ultraviolet absorbers. However, from this information it was not possible to conclude that particularly advantageous combinations can be obtained with certain selected UV absorbers.

[0058] The compounds (B) are all known and are characterized in more detail below:

[0059] Ba) The compound of the formula II is known from EP-A-1 046 391.

[0060] Bb) The compound of the formula III is known from EP-A-0 916335.

[0061] Bc) The compound of the formula IV has the CAS No. 88122-99-0 and is sold under the trade name Uvinul® T150 (BASF).

[0062] Bd) The compound of the formula V has the CAS No. 187393-00-6.

[0063] Be) The compound of the formula VI has the CAS No. 103597-45-1 and is sold under the trade name Tinosorb® M (CIBA).

[0064] Bf) The compound of the formula VII has the CAS No. 155633-54-8 and is known under the trade name Mexoryl® XL (CHIMEX).

[0065] Bg) The compounds or mixtures of compounds of the formula VIII are known from EP-A 0920859. Of the compounds of the formulae VIIIa and/or VIIIb, those with the CAS numbers 208391-15-5, 208391-15-5D, 177955-90-7, 177955-90-7D and 177995-90-7DP are particularly suitable.

[0066] Bh) The compound of the formula IX has the CAS No. 154702-15-5 and is sold under the trade name Uvasorb® HEB (BV Sigma).

[0067] Bi) The compound of the formula X has the CAS No. 6197-30-4 and is sold under the trade name Uvinul® N539 (BASF).

[0068] Bj) The compound of the formula XI has the CAS No. 180898-37-7 (Haarmann & Reimer).

[0069] Bk) The compound of the formula XII has the CAS No. 131-55-5 and is sold under the trade name Uvinul® D50 (BASF).

[0070] In the sunscreen combinations to be used according to the invention, it is possible for not only individual compounds (Ba) to (Bk) to be present, but also mixtures of two or more of these compounds.

[0071] The present invention further provides cosmetic and pharmaceutical preparations which have 0.1 to 40% by weight, preferably 1 to 25% by weight, based on the total amount of the cosmetic and pharmaceutical preparation, of a sunscreen combination comprising a

[0072] A) compound absorbing essentially in the UV-A region and

[0073] B) further compounds absorbing in the UV-A region, in the UV-B region and over both regions,

[0074]  where the constituent absorbing in the UV-A region consists of

[0075] A) effective amounts of the compound of the formula I

[0076]  and the constituent

[0077] B) comprises effective amounts of one or more compounds chosen from the group consisting of

[0078] Ba) hydroxybenzophenone of the formula IIa

[0079] Bb) diarylbutadiene of the formula IIIa

[0080] Bc) the compound of the formula IV

[0081] Bd) the compound of the formula V

[0082] Be) the compound of the formula VI

[0083] Bf) the compound of the formula VII

[0084] Bg) an organosiloxane benzalmalonate of the formula VIIa

[0085]  in which

[0086] V₁′ is the group

[0087] V₁ is a methyl group or V₁′, or of the formula VIIIb

[0088]  in which V₂′ is the group of the structure

[0089] V₂ is a methyl group or V₂′

[0090]  or mixtures of compounds of the formulae VIIa and VIIIb,

[0091] where t is a value up to 100 and u is a value up to 20, with the proviso that u=0 when V₁=V₁′ and/or V₂=V₂′, and u is a value from 1 to 20 when V₁=CH₃ and/or V₂=CH₃,

[0092] Bh) the compound of the formula IX

[0093] Bi) the compound of the formula X

[0094] Bj) the compound of the formula XI

[0095]  in which X is hydrogen, sodium, potassium, ammonium or triethanolammonium,

[0096] Bk) the compound of the formula XII

[0097] optionally together with further compounds which absorb in the UV-A-region and UV-B-region and which are known per se for cosmetic and pharmaceutical preparations, where the UV-A-absorbing compounds are usually used in a lesser amount than the UV-B-absorbing compounds.

[0098] The sunscreen-containing cosmetic and pharmaceutical preparations are, as a rule, based on a carrier which comprises at least one oil phase. However, preparations based solely on water are also possible if compounds having hydrophilic substituents are used. Accordingly, oils, oil-in-water and water-in-oil emulsions, creams and pastes, lip-protection stick compositions or non-greasy gels are suitable.

[0099] Suitable emulsions are inter alia also O/W macroemulsions, O/W microemulsions or O/W/O emulsions containing the compound of the formula I in dispersed form, the emulsions being obtainable by phase inversion technology, as in DE-A-197 26 121. Here, the particle size of the compound of the formula I is chosen such that it is 3 μm or less, preferably 1 μm or less than the average particle size.

[0100] Conventional cosmetic auxiliaries which may be suitable as additives are, for example, coemulsifiers, fats and waxes, stabilizers, thickeners, biogenic active substances, film formers, fragrances, dyes, pearlizing agents, preservatives, pigments, electrolytes (e.g. magnesium sulfate) and pH regulators. Suitable and preferred coemulsifiers are known W/O and also O/W emulsifiers such as polyglycerol esters, sorbitan esters or partially esterified glycerides. Typical examples of fats are glycerides; waxes which may be mentioned are, inter alia, beeswax, paraffin wax or microwaxes, possibly combined with hydrophilic waxes. Stabilizers which can be employed are metal salts of fatty acids such as, for example, magnesium stearate, aluminum stearate and/or zinc stearate. Examples of suitable thickeners are crosslinked polyacrylic acids and derivatives thereof, polysaccharides, in particular xanthan gum, guar guar, agar agar, alginates and tyloses, carboxymethylcellulose and hydroxyethylcellulose, also fatty alcohols, monoglycerides and fatty acids, polyacrylates, polyvinyl alcohol and polyvinylpyrrolidone. Examples of biogenic active ingredients are plant extracts, protein hydrolysates and vitamin complexes. Examples of customary film formers are hydrocolloids such as chitosan, microcrystalline chitosan or quaternized chitosan, polyvinylpyrrolidone, vinylpyrrolidone/vinyl acetate copolymers, polymers of the acrylic acid series, quaternary cellulose derivatives and similar compounds. Examples of suitable preservatives are formaldehyde solution, p-hydroxybenzoate or sorbic acid. Examples of suitable pearlizing agents are glycol distearic esters such as ethylene glycol distearate, but also fatty acids and fatty acid monoglycol esters. Dyes which can be used are the substances suitable and approved for cosmetic purposes, as listed, for example, in the publication “Kosmetische Färbemittel” [Cosmetic Colorants] from the Farbstoffkommission der Deutschen Forschungsgemeinschaft [Dyes Commission of the German Research Society], published by Verlag Chemie, Weinheim, 1984. These dyes are normally used in a concentration of from 0.001 to 0.1% by weight, based on the total mixture.

[0101] An additional content of antioxidants is generally preferred. Thus, it is possible to use as favorable antioxidants all antioxidants which are customary or suitable for cosmetic and/or dermatological applications.

[0102] The antioxidants are advantageously chosen from the group consisting of amino acids (e.g. glycine, histidine, tyrosine, tryptophan) and derivatives thereof, imidazoles (e.g. urocanic acid) and derivatives thereof, peptides such as D,L-carnosine, D-carnosine, L-carnosine and derivatives thereof (e.g. anserine), carotenoids, carotenes (e.g. β-carotene, lycopene) and derivatives thereof, chlorogenic acid and derivatives thereof, lipoic acid and derivatives thereof (e.g. dihydrolipoic acid), aurothioglucose, propylthiouracil and other thiols (e.g. thioredoxin, glutathione, cysteine, cystine, cystamine and the glycosyl, N-acetyl, methyl, ethyl, propyl, amyl, butyl, and lauryl, palmitoyl, oleyl, γ-linoleyl, cholesteryl and glyceryl esters thereof) and salts thereof, dilauryl thiodipropionate, distearyl thiodipropionate, thiodipropionic acid and derivatives thereof (esters, ethers, peptides, lipids, nucleotides, nucleosides and salts), and sulfoximine compounds (e.g. buthionine sulfoximines, homocysteine sulfoximines, buthionine sulfones, penta-, hexa-, heptathionine sulfoximine) in very low tolerated doses (e.g. pmol to μmol/kg), and also (metal) chelating agents (e.g. α-hydroxy fatty acids, palmitic acid, phytic acid, lactoferrin), α-hydroxy acids (e.g. citric acid, lactic acid, malic acid), humic acid, bile acid, bile extracts, bilirubin, biliverdin, EDTA and derivatives thereof, unsaturated fatty acids and derivatives thereof (e.g. γ-linolenic acid, linoleic acid, oleic acid), folic acid and derivatives thereof, ubiquinone and ubiquinol and derivatives thereof, vitamin C and derivatives thereof (e.g. ascorbyl palmitate, Mg ascorbylphosphate, ascorbylacetate), tocopherol and derivatives (e.g. vitamin E acetate, tocotrienol), vitamin A and derivatives (vitamin A palmitate), and coniferyl benzoate of benzoin resin, rutinic acid and derivatives thereof, α-glycosylrutin, ferulic acid, furfurylideneglucitol, carnosine, butylhydroxytoluene, butylhydroxyanisole, nordihydroguaiacic acid, nordihydroguaiaretic acid, trihydroxybutyrophenone, uric acid and derivatives thereof, mannose and derivatives thereof, zinc and derivatives thereof (e.g. ZnO, ZnSO₄), selenium and derivatives thereof (e.g. selenomethionine), stilbenes and derivatives thereof (e.g. stilbene oxide, trans-stilbene oxide).

[0103] The amount of the abovementioned antioxidants (one or more compounds) in the preparations is preferably from 0.001 to 30% by weight, particularly preferably from 0.05 to 20% by weight, in particular from 1 to 10% by weight, based on the total weight of the preparation.

[0104] If vitamin E and/or derivatives thereof are used as the antioxidant(s), it is advantageous to choose their particular concentration from the range 0.001 to 10% by weight, based on the total weight of the formulation.

[0105] If vitamin A and/or derivatives thereof, or carotenoids are the antioxidant(s), it is advantageous to choose their particular concentration from the range 0.001 to 10% by weight, based on the total weight of the formulation.

[0106] Customary oil components in cosmetics are, for example, paraffin oil, glyceryl stearate, isopropyl myristate, diisopropyl adipate, cetylstearyl 2-ethylhexanoate, hydrogenated polyisobutene, vaseline, caprylic/capric triglycerides, microcrystalline wax, lanolin and stearic acid.

[0107] The total amount of auxiliaries and additives can be from 1 to 80% by weight, preferably from 6 to 40% by weight, and the nonaqueous fraction (“active substance”) can be from 20 to 80% by weight, preferably from 30 to 70% by weight, based on the compositions. The compositions can be prepared in a manner known per se, i.e. for example by hot, cold, hot-hot/cold or PIT emulsification. This is a purely mechanical process; no chemical reaction takes place.

[0108] Such sunscreen preparations can accordingly be in liquid, paste or solid form, for example as water-in-oil creams, oil-in-water creams and lotions, aerosol foam creams, gels, oils, marking pencils, powders, sprays or alcoholic-aqueous lotions.

[0109] Finally, it is also possible to co-use further substances which absorb in the UV region and are known per se provided they are stable in the overall system of the combination of UV filters to be used according to the invention.

[0110] Suitable UV filter substances which can be additionally used with the sunscreen combinations to be used according to the invention are any UV-A and UV-B filter substances. Examples which may be mentioned are: CAS No. No. Substance (= acid) 1 4-Aminobenzoic acid  150-13-0 2 3-(4′-Trimethylammonium)benzylidenbornan-2- 52793-97-2  one methylsulfate 3 3,3,5-Trimethylcyclohexyl salicylate  118-56-9 (homosalate) 4 2-Hydroxy-4-methoxybenzophenone  131-57-7 (oxybenzone) 5 2-Phenylbenzimidazole-5-sulfonic acid and its 27503-81-7  potassium, sodium and triethanolamine salts 6 3,3′-(1,4-Phenylenedimethine)-bis(7,7-dimethyl- 90457-82-2  2-oxobicyclo[2.2.1]heptane-1-methanesulfonic acid) and its salts 7 Polyethoxyethyl 4-bis(polyethoxy)aminobenzoate 113010-52-9  8 2-Ethylhexyl 4-dimethylaminobenzoate 21245-02-3  9 2-Ethylhexyl salicylate  118-60-5 10 2-Ethylhexyl 4-methoxycinnamate 5466-77-3 11 2-Hydroxy-4-methoxybenzophenone-5-sulfonic 4065-45-6 acid (sulisobenzone) and the sodium salt 12 3-(4′-Sulfo)benzylidenebornan-2-one and salts 58030-58-6  13 3-Benzylidenebornan-2-one 16087-24-8  14 1-(4′-Isopropylphenyl)-3-phenylpropane- 63260-25-9  1,3-dione 15 4-Isopropylbenzyl salicylate 94134-93-7  16 3-Imidazol-4-yl-acrylic acid and its ethyl  104-98-3 ester 17 Ethyl 2-cyano-3,3-diphenylacrylate 5232-99-5 18 Menthyl o-aminobenzoate or:  134-09-8 5-methyl-2-(1-methylethyl) 2-aminobenzoate 19 Glyceryl p-aminobenzoate or:  136-44-7 1-glyceryl 4-aminobenzoate 20 2,2′-Dihydroxy-4-methoxybenzophenone  131-53-3 (dioxybenzone) 21 2-Hydroxy-4-methoxy-4-methylbenzophenone 1641-17-4 (mexonone) 22 Triethanolamine salicylate 2174-16-5 23 Dimethoxyphenylglyoxalic acid or: 4732-70-1 sodium 3,4-dimethoxyphenylglyoxalate 24 3-(4′-sulfo)benzylidenebornan-2-one and its 56039-58-8  salts 25 4-tert-butyl-4′-methoxydibenzoylmethane 70356-09-1  26 3-(4-Methylbenzylidene)camphor 36861-47-9 

[0111] In addition, the cosmetic and dermatological preparations according to the invention can advantageously comprise further inorganic pigments based on metal oxides and/or other metal compounds which are insoluble or virtually insoluble in water, in particular the oxides of iron (e.g. Fe₂O₃), zirconium (ZrO₂), silicon (SiO₂), manganese (e.g. MnO), aluminum (Al₂O₃), cerium (e.g. Ce₂O₃), mixed oxides of the corresponding metals, and admixtures of such oxides.

[0112] For the purposes of the present invention, it is particularly advantageous, but not obligatory, for the inorganic pigments to be present in hydrophobic form, i.e. to have been surface-treated to repel water. This surface treatment can involve providing the pigments with a thin hydrophobic layer in a manner known per se, as described in DE-A-33 14 742.

[0113] To protect human hair against UV rays, the sunscreen combinations to be used according to the invention can be incorporated into shampoos, lotions, gels, hairsprays, aerosol foam creams or emulsions in concentrations of from 0.1 to 10% by weight, preferably from 1 to 7% by weight. The respective formulations can be used, inter alia, for washing, coloring and for styling the hair.

[0114] The sunscreen combinations to be used according to the invention are readily soluble in cosmetic oils and can be easily incorporated into cosmetic formulations. The emulsions prepared with the novel sunscreen combinations are in particular characterized by their high stability, the sunscreen combinations themselves by their high photostability, and the preparations prepared with the sunscreen combinations by their pleasant feel on the skin.

[0115] The UV filter action of the sunscreen combinations to be used according to the invention can also be utilized for stabilizing active ingredients and auxiliaries in cosmetic and pharmaceutical formulations.

[0116] The examples below illustrate the use of the novel sunscreen combinations in more detail.

EXAMPLES Example 1

[0117] Standardized Method to Determine Photostability (Sun Test)

[0118] A 5% by weight alcoholic solution of the sunscreen to be tested is applied, using an Eppendorf pipette (20 μl), to the milled area on a small glass plate. Owing to the presence of the alcohol, the solution distributes uniformly on the roughened glass surface. The amount applied corresponds to the amount of sunscreen required to obtain an average sun protection factor in sun creams. In the test, 4 small glass plates are irradiated in each case. The evaporation time and the irradiation each last for 30 minutes. The glass plates are cooled slightly during the irradiation by a water cooling system located at the base of the sun test apparatus. The temperature inside the sun test apparatus during the irradiation is 40° C. After the samples have been irradiated, they are washed with ethanol into a dark 50 ml volumetric flask and measured using a photometer. The blank samples are applied in the same way to small glass plates and evaporated at room temperature for 30 minutes. Like the other samples, they are washed off with ethanol and diluted to 100 ml and measured.

[0119] General Procedure for Preparing Emulsions for Cosmetic Purposes

[0120] All of the oil-soluble constituents are heated to 85° C. in a stirred vessel. When all of the constituents are molten or are present as liquid phase, the aqueous phase is incorporated with homogenization. The emulsion is cooled to about 40° C. with stirring, is perfumed and homogenized, and is then cooled to 25° C. with continuous stirring. Preparations Mass content (% by weight) Example 2-Lip care composition ad 100 Eucerinum anhydricum 10.00  glycerol Filter combination consisting of 5.00 (I) 8.00 (II) 10.00  TiO₂ 5.00 ZnO₂ 4.00 castor oil 4.00 pentaerythrityl stearate/caprate/caprylate/adipate 3.00 glyceryl stearate SE 2.00 beeswax 2.00 microcrystalline wax 2.00 quaternium-18 bentonite 1.50 PEG-45/dodecyl glycol copolymer Example 3-Lip care composition ad 100 Eucerinum anhydricum 10.00  glycerol Filter combination consisting of 1.00 (I) 8.00 (II) 4.00 (V) 10.00  TiO₂ 5.00 ZnO₂ 4.00 castor oil 4.00 pentaerythrityl stearate/caprate/caprylate/adipate 3.00 glyceryl stearate SE 2.00 beeswax 2.00 microcrystalline wax 2.00 quaternium-18 bentonite 1.50 PEG-45/dodecyl glycol copolymer Example 4-Sunblock composition containing micropigments ad 100 water 6.00 PEG-7 hydrogenated castor oil Filter combination consisting of 2.00 (I) 3.00 (V) 10.00  (II) 3.00 (X) 6.00 TiO₂ 5.00 mineral oil 5.00 isoamyl p-methoxycinnamate 5.00 propylene glycol 3.00 jojoba oil 2.00 PEG-45/dodecyl glycol copolymer 1.00 dimethicone 0.50 PEG-40 hydrogenated castor oil 0.50 tocopheryl acetate 0.50 phenoxyethanol 0.20 EDTA Example 5-Sunblock composition containing micropigments ad 100 water 6.00 PEG-7 hydrogenated castor oil Filter combination consisting of 2.00 (I) 3.00 (IV) 10.00  (II) 3.00 (X) 6.00 TiO₂ 5.00 mineral oil 5.00 isoamyl p-methoxycinnamate 5.00 propylene glycol 3.00 jojoba oil 2.00 PEG-45/dodecyl glycol copolymer 1.00 dimethicone 0.50 PEG-40 hydrogenated castor oil 0.50 tocopheryl acetate 0.50 phenoxyethanol 0.20 EDTA Example 6-Non-greasy gel ad 100 water Filter combination consisting of 2.00 (I) 3.00 (VI) 8.00 (II) 1.00 (X) 7.00 TiO₂ 5.00 glycerol 5.00 PEG-25 PABA 0.40 acrylate C₁₀-C₃₀ alkyl acrylate crosspolymer 0.30 imidazolidinylurea 0.25 hydroxyethylcellulose 0.25 sodium methylparaben 0.20 disodium EDTA 0.15 fragrance 0.15 sodium propylparaben 0.10 sodium hydroxide Example 7-Non-greasy gel ad 100 water Filter combination consisting of 1.00 (I) 4.00 (VI) 8.00 (II) 1.00 (X) 7.00 TiO₂ 5.00 glycerol 5.00 PEG-25 PABA 0.40 acrylate C₁₀-C₃₀ alkyl acrylate crosspolymer 0.30 imidazolidinylurea 0.25 hydroxyethylcellulose 0.25 sodium methylparaben 0.20 disodium EDTA 0.15 fragrance 0.15 sodium propylparaben 0.10 sodium hydroxide Example 8-Sun cream ad 100 water Filter combination consisting of 2.00 (I) 3.00 (XIV) 8.00 (II) 1.00 (X) 8.00 TiO₂ 5.00 ZnO₂ 6.00 PEG-7 hydrogenated castor oil 6.00 mineral oil 5.00 isopropyl palmitate 0.30 imidazolidinylurea 3.00 jojoba oil 2.00 PEG-45/dodecyl glycol copolymer 0.60 magnesium stearate 0.50 tocopheryl acetate 0.25 methylparaben 0.20 disodium EDTA 0.15 propylparaben Example 9-Sun cream ad 100 water Filter combination consisting of 3.00 (I) 3.00 (XI) 8.00 (II) 8.00 TiO₂ 5.00 ZnO₂ 6.00 PEG-7 hydrogenated castor oil 6.00 mineral oil 5.00 isopropyl palmitate 0.30 imidazolidinylurea 3.00 jojoba oil 2.00 PEG-45/dodecyl glycol copolymer 0.60 magnesium stearate 0.50 tocopheryl acetate 0.25 methylparaben 0.20 disodium EDTA 0.15 propylparaben Example 10-Water-resistant sun cream ad 100 water Filter combination consisting of 1.00 (I) 4.00 (IX) 8.00 (II) 2.00 (X) 3.00 TiO₂ 5.00 PEG-7 hydrogenated castor oil 5.00 propylene glycol 4.00 isopropyl palmitate 4.00 caprylic/capric triglyceride 4.00 glycerol 3.00 jojoba oil 1.50 PEG-45/dodecyl glycol copolymer 1.50 dimethicone 0.70 magnesium sulfate 0.50 magnesium stearate 0.15 fragrance Example 11-Water-resistant sun cream ad 100 water Filter combination consisting of 2.00 (I) 5.00 (XII) 2.00 TiO₂ 5.00 PEG-7 hydrogenated castor oil 5.00 propylene glycol 4.00 isopropyl palmitate 4.00 caprylic/capric triglyceride 4.00 glycerol 3.00 jojoba oil 1.50 PEG-45/dodecyl glycol copolymer 1.50 dimethicone 0.70 magnesium sulfate 0.50 magnesium stearate 0.15 fragrance Example 12-Sun milk ad 100 water 10.00  mineral oil 6.00 PEG-7 hydrogenated castor oil 5.00 isopropyl palmitate Filter combination consisting of 3.00 (I) 5.50 (VIII) 3.00 caprylic/capric triglyceride 3.00 jojoba oil 2.00 PEG-45/dodecyl glycol copolymer 0.70 magnesium sulfate 0.60 magnesium stearate 0.50 tocopheryl acetate 3.00 glycerol 0.25 methylparaben 0.15 propylparaben 0.05 tocopherol Example 13-Sun milk ad 100 water 10.00  mineral oil 6.00 PEG-7 hydrogenated castor oil 5.00 isopropyl palmitate Filter combination consisting of 1.00 (I) 4.00 (XIV) 3.50 (II) 3.00 caprylic/capric triglyceride 3.00 jojoba oil 2.00 PEG-45/dodecyl glycol copolymer 0.70 magnesium sulfate 0.60 magnesium stearate 0.50 tocopheryl acetate 3.00 glycerol 0.25 methylparaben 0.15 propylparaben 0.05 tocopherol 

We claim:
 1. The use of sunscreen combinations comprising a A) compound absorbing essentially in the UV-A region and B) further compounds absorbing in the UV-A region, in the UV-B region and over both regions,  where the constituent absorbing in the UV-A region consists of A) effective amounts of at least one of the compounds of the formula I

 in which the substituents R¹ to R³, independently of one another, are C₁-C₈-alkyl  and the constituent B) comprises effective amounts of one or more compounds chosen from the group consisting of Ba) hydroxybenzophenones of the formula II

 in which the substituents, independently of one another, have the following meanings: R⁴ and R⁵ are hydrogen, C₁-C₁₂-alkyl, C₃-C₁₀-cycloalkyl, where the substituents R⁴ and R⁵ may, together with the nitrogen atom to which they are bonded, form a 5- or 6-membered ring and R⁶ hydrogen, C₁-C₁₂-alkyl, C₃-C₁₀-cycloalkyl; Bb) diarylbutadienes of the formula III

 in which the substituents R⁷ and R⁸, independently of one another, may be hydrogen, C₁-C₁₂-alkyl or C₃-C₁₀-cycloalkyl, Bc) the compound of the formula IV

Bd) the compound of the formula V

Be) the compound of the formula VI

Bf) the compound of the formula VII

Bg) an organosiloxane benzalmalonate of the formula VIIIa

 in which V₁′ is the group

V₁ is a methyl group or V₁′, or of the formula VIIIb

 in which V₂′ is the group of the structure

V₂ is a methyl group or V₂′  or mixtures of compounds of the formulae VIIIa and VIIIb, where t is a value up to 100 and u is a value up to 20, with the proviso that u=0 when V₁=V₁′ and/or V₂=V₂′, and u is a value from 1 to 20 when V₁=CH₃ and/or V₂=CH₃, Bh) the compound of the formula IX

Bi) the compound of the formula X

Bj) the compound of the formula XI

 in which X is hydrogen, sodium, potassium, ammonium or triethanolammonium, Bk) the compound of the formula XII

as photostable UV filters in cosmetic and pharmaceutical preparations for protecting human skin or human hair against solar rays, optionally together with further compounds which absorb in the UV region and which are known per se for cosmetic and pharmaceutical preparations.
 2. The use of sunscreen combinations as claimed in claim 1, which comprise the constituent A) of the formula I in amounts of at least 5% by weight, based on the sunscreen combination.
 3. A cosmetic or pharmaceutical preparation comprising sunscreen combinations for the protection of the human epidermis or human hair against UV light in the range from 280 to 400 nm, which comprises, in a cosmetically or pharmaceutically suitable carrier, as photostable UV filter, an effective amount of sunscreen combinations which have A) a compound absorbing essentially in the UV-A region and B) further compounds absorbing in the UV-A region, in the UV-B region and over both regions,  where the constituent absorbing in the UV-A region consists of A) effective amounts of the compound of the formula

 and the constituent B) comprises effective amounts of one or more compounds chosen from the group consisting of Ba) hydroxybenzophenone of the formula IIa

Bb) diarylbutadiene of the formula IIIa

Bc) the compound of the formula IV

Bd) the compound of the formula V

Be) the compound of the formula VI

Bf) the compound of the formula VII

Bg) an organosiloxane benzalmalonate of the formula VIIIa

 in which V₁′ is the group

V₁ is a methyl group or V₁′, or of the formula VIIIb

 in which V₂′ is the group of the structure

V₂ is a methyl group or V₂′  or mixtures of compounds of the formulae VIIIa and VIIIb, where t is a value up to 100 and u is a value up to 20, with the proviso that u=0 when V₁=V₁′ and/or V₂=V₂′, and u is a value from 1 to 20 when V₁=CH₃ and/or V₂=CH₃, Bh) the compound of the formula IX

Bi) the compound of the formula X

Bj) the compound of the formula XI

 in which X is hydrogen, sodium, potassium, ammonium or triethanolammonium, Bk) the compound of the formula XII

optionally together with further compounds which absorb in the UV region and which are known per se for cosmetic and pharmaceutical preparations.
 4. A cosmetic or pharmaceutical preparation comprising sunscreen combinations as claimed in claim 3, where the sunscreen combinations comprise the constituent of the formula I in amounts of at least 5% by weight, based on the sunscreen combination. 